BackForwardInstrument:  EDI (MMS) 

Instrument details
Acronym EDI (MMS)
Full name Electron Drift Instrument
Purpose Observation of the magnetic and electric fields across the Magnetosphere
Short description Based on two electron guns. The electric and magnetic fields are observed by measuring the drift of ~1 keV electrons emitted from one gun and received by the other one, and viceversa. Dynamic range of the magnetic field: 5-1000 nT with resolution 0.1 nT @ maximum of the dynamics; of the electric field: 0.1-10 mV/m
Background Part of a package of instruments to implement the SMART (Solving Magnetospheric Acceleration, Reconnection, and Turbulence) mission
Scanning Technique 4 satellites co-flying in tetrahedral pattern, moving to different positions into the Magnetosphere for 3-D field reconstruction
Resolution N/A
Coverage / Cycle Full magnetospheric volume; sampling at 6 ms intervals
Mass Power Data Rate


Providing Agency NASA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 2015 to 2024
Last update: 2021-10-02
Detailed characteristics
Satellites this instrument is flying on

Note: a red tag indicates satellites no longer operational, a green tag indicates operational satellites, a blue tag indicates future satellites

Instrument classification
  • Solar and space environment monitors
  • Field or radiowave sensor
WIGOS Subcomponents
  • Subcomponent 2
  • Magnetospheric energetic particles and magnetometers
  • Geomagnetic field sensor [in LEO and cross magnetosphere]
  • Electric field sensor [in LEO and cross magnetosphere]
Mission objectives
Primary mission objectives
  • Electric Field
  • Geomagnetic field
Evaluation of Measurements

The following list indicates which measurements can typically be retrieved from this category of instrument. To see a full Gap Analysis by Variable, click on the respective variable.

Note: table can be sorted by clicking on the column headers
Note: * Primary mission objective.
VariableRelevance for measuring this variableOperational limitationsExplanation
Geomagnetic field*1 - primaryNo specific limitation.Cluster in magnetosphere, scalar, narrow dynamics, high resolution
Electric Field*1 - primaryNo specific limitation.Cluster in the magnetosphere. Electric field, poor dynamic range